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EVALUATIONS OF INSECTICIDE PERFORMANCE FOR CONTROL OF ALFALFA WEEVIL LARVAE AND APHIDS, 2005

EVALUATIONS OF INSECTICIDE PERFORMANCE FOR CONTROL OF ALFALFA WEEVIL LARVAE AND APHIDS, 2005 (F1) ALFALFA: Medicago sativa L. “OK 49” EVALUATIONS OF INSECTICIDE PERFORMANCE FOR CONTROL OF ALFALFA WEEVIL LARVAE AND APHIDS, 2005 P.G. Mulder, Jr. Department of Entomology and Plant Pathology Oklahoma State University Stillwater, OK 74078-3033 405-744-5531 FAX 405-744-6039 Email: philmul@okstate.edu S.K. Seuhs Alfalfa Weevil (AW): Hypera postica (Gyllenhal) Pea aphid (PA): Acyrthosiphon pisum (Harris) Blue alfalfa aphid (BAA): Acyrthosiphon kondoi Shinji Cowpea aphid (CA): Aphis craccivora Koch Seven chemical insecticides at varying rates and combinations were evaluated for efficacy in controlling AW larvae and aphids infesting the first crop of a third year stand of “OK 49” alfalfa at the Agronomy Research Station, Stillwater, OK. Pretreatment samples (stubble) revealed very few larvae or aphids; however, samples taken at AW threshold indicated a mean AW population of 73.25 larvae/25stems, while aphid populations remained extremely low (0.25 aphids/stem). The stubble treatment of Warrior was applied on 22 Feb coinciding with timing for annual weed control. Threshold for AW was reached and insecticides were applied on 1 March using a CO pressurized sprayer calibrated to deliver 20 gpa at 19 psi through seven, flat fan nozzles when traveling at 3 mph. Treatments were arranged in a RCB design using plots 3.9 × 9.1 m in size, replicated 4 times. Sampling was conducted 3 and 7 DAT (stubble) and continued 3,7,14, 22, 28 and 35 DAT from the first threshold application, by pulling 25 stems per plot and placing them in standard Berlese funnels to extract insects for counting. Dry matter yields were estimated for first harvest on 3 May by removing forage from a 1 × 5 m area in each plot using a flail-type harvester. Subsamples were dried for determination of moisture content and yields were calculated on a dry weight/acre basis. Weather conditions for the first three days after threshold treatment decreased activity of insects, with no rainfall and a mean daily high temperature of 51.9° F. During the remainder of the trial, through 3 May, a total of 1.09 inches of rainfall occurred and the mean daily high temperature was 52.2 F. The population density of AW was above the economic threshold at the time of treatment and rose to 209.3 larvae/25 stems at 14 DAT in the untreated alfalfa. Samples taken 3 and 7 d after the stubble treatment revealed significant control of AW and aphids even before thresholds were reached in untreated alfalfa (Table 1). These plots were only sprayed during the stubble timing. During the first week after threshold treatment, all insecticides decreased AW larval densities below levels recovered in untreated alfalfa (Table 2). Average percent control for AW was calculated from infestations recovered 3 to 35 DAT. Throughout the test period; most insecticides significantly reduced AW populations below levels recovered in untreated alfalfa. Three DAT, specific insecticides began to perform better than others and this performance remained consistent throughout the trial. Average percent control of AW larvae from 3 DAT to 35 DAT ranged from a low of 10.83 % for Imidan 70 WP (1.0 lb. A.I./acre) to a high of 93.5 % for Warrior 1 EC (stubble - 0.03lb. A.I./acre) (Table 2). In addition, Imidan at the higher rate (1.3 lb. AI/acre) only provided 31.33 % control of AW larvae, while all other formulations provided 70 % control or better (Table 2). From 3DAT to 22DAT, average percent control of all aphids sampled ranged from a low of - 43.75% with Imidan 70WP (1.3 lb.AI/Acre) to a high of + 99.48% with Warrior 1 EC (0.03 lb./AI/acre) (Tables 3-6). Throughout the trial period, the two Warrior treatments and Proaxis provided the greatest and most consistent levels of aphid control. In contrast, alfalfa treated with Imidan often experienced aphid populations in excess of untreated plants. Yield of alfalfa at first harvest ranged from 5563.52 lb./acre in alfalfa treated with Warrior 1 EC (0.03 lb. AI/acre - stubble) to 2706.70 lb./acre in the untreated alfalfa. All treatments yielded significantly greater than the untreated alfalfa with the exception of Imidan 70WP (1.0 lb. AI/acre). The higher rate of Imidan 70WP also performed poorly and yielded significantly less than alfalfa treated with the other insecticides. Table 1 Mean no insects/25 stems (Stubble) AW larvae PA** BAA** CPA** Total aphids Treatment/ Rate/ formulation lbs ai/A 3DAT* 7DAT* 3DAT* 7DAT* 3DAT* 7 DAT* 3DAT* 7DAT* 3DAT* 7DAT* Warrior 1 EC Stubble 0.03 37.5a 33.0a 0.0a 0.0a 0.3a 0.3a 0.3a 0.0a 0.5a 0.5a Untreated check 90.2b 123.0b 4.3b 2.8b 7.5b 5.0a 1.5a 1.5a 13.3b 10.5b * Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). ** PA = Pea Aphid. BAA = Blue Alfalfa Aphid. SAA = Spotted Alfalfa Aphid. CPA = Cow Pea Aphid. DAT = Days after treatment. Stubble sample date was 7 days prior to threshold treatment (2-22-05). Table 2 Mean no. AW larvae/25 stems Treatment/ Rate/ Average** Yield* formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control lbs/A Imidan 70 WP 1.0 129.8ab 141.0a 151.8b 180.0a 169.0a 165.5a 10.83 3082.85bc Imidan 70 WP 1.3 140.8a 95.7b 107.8c 119.3b 134.8b 120.3b 31.33 3338.32b Baythroid 2 EC 0.0313 77.0cd 63.3c 46.3de 28.0c 33.8c 25.3c 73.83 5299.25a Baythroid 2 EC 0.0375 80.5c 74.0bcd 48.3de 30.3c 27.5c 25.8c 72.67 5130.29a Baythroid XL 0.0188 79.5cd 48.3ce 59.3de 23.8c 25.8c 18.8c 75.83 5210.10a Baythroid XL 0.022 73.5cd 64.3c 55.5de 22.5c 28.8c 34.5c 73.33 5305.92a Warrior 1 EC 0.025 67.8cd 58.3c 52.5de 22.3c 20.3c 16.5c 77.33 5216.52a Baythroid 2 EC + 0.0313 + 53.0cd 45.8de 35.8ef 31.8c 17.8c 19.8c 80.33 5341.10a Lorsban 4E 0.25 Warrior 1 EC 0.03 66.5cd 58.3c 42.5de 9.8c 4.8c 16.0c 83.50 5538.34a Warrior 1 EC 0.03 31.5d 27.3e 14.3 f 11.0c 4.3c 8.5c 93.50 5563.52a Stubble Proaxis 0.5 EC 0.015 88.5bc 77.7bc 61.0d 25.8c 23.3c 24.0c 71.33 5330.10a Untreated check 163.0a 166.3a 209.3a 183.5a 167.8a 169.5a 2706.70c *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 35DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 3 Mean no. PA/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control Imidan 70 WP 1.0 2.0b 5.5b 17.0a 7.3ab 13.8ab 90.0a -2.75 Imidan 70 WP 1.3 7.8a 5.5b 4.8c 13.3a 23.5a 41.3bc -78.25 Baythroid 2 EC 0.0313 0.5b 3.3bc 6.3abc 1.0bc 10.0ab 21.8c 76.00 Baythroid 2 EC 0.0375 0.3b 2.0bc 9.5abc 0.8c 5.5b 43.8c 75.75 Baythroid XL 0.0188 0.3b 2.5bc 8.0abc 6.0bc 9.5b 24.8c 61.50 Baythroid XL 0.022 1.5b 3.0bc 5.8bc 1.0bc 9.8b 27.3c 67.50 Warrior 1 EC 0.025 0.0b 0.8c 1.3c 0.0c 1.0b 21.0c 96.50 Baythroid 2 EC + 0.0313 + 0.5b 0.0c 1.8c 2.8bc 3.3b 35.8c 84.25 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0b 0.0c 1.3c 0.0c 4.0b 45.3bc 98.00 Warrior 1 EC 0.03 0.0b 0.8c 0.0c 0.0c 1.0b 33.8c 98.50 Stubble Proaxis 0.5 EC 0.015 0.3 b 0.8 c 1.5c 0.0c 3.0b 22.3c 93.50 Untreated check 2.8 b 12.5 a 15.8ab 8.3a 3.0b 77.3ab * Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). ** Average % control calculated from 3DAT to 22DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 4 Mean no. BAA/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control 70 WP 1.0 3.8bc 0.5b 13.8a 3.3ab 8.3ab 50.5a -.75 Imidan 70 WP 1.3 8.5a 25.0a 5.0bc 7.8a 17.3a 23.0abc -145.25 Baythroid 2 EC 0.0313 1.5c 2.0b 1.8bc 1.0b 3.8b 10.3bc 77.00 Baythroid 2 EC 0.0375 2.0bc 0.8b 3.3bc 0.3b 3.5b 24.0abc 78.00 Baythroid XL 0.0188 0.8c 0.5b 2.5bc 0.8b 6.0ab 12.0bc 83.50 Baythroid XL 0.022 2.8bc 0.8b 1.5bc 0.3b 7.3ab 8.8bc 79.75 Warrior 1 EC 0.025 0.5c 0.0b 0.0c 0.0b 2.0b 8.0c 98.00 Baythroid 2 EC + 0.0313 + 1.5c 0.3b 0.5bc 2.0b 5.0b 8.3c 79.50 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0c 0.0b 0.3bc 0.3b 2.5b 15.8bc 97.50 Warrior 1 EC 0.03 0.8c 0.0b 0.3bc 0.0b 1.8b 11.8bc 96.00 Stubble Proaxis 0.5 EC 0.015 1.0c 0.3b 0.8bc 0.0b 5.8ab 16.0bc 92.50 Untreated check 6.0ab 8.3ab 8.8ab 4.3a 3.8b 40.5ab *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 22DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 5 Mean no. CA/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control Imidan 70 WP 1.0 0.3ab 0.3b 2.3b 9.0ab 3.3b 67.0ab 74.00 Imidan 70 WP 1.3 0.5ab 1.3ab 11.5b 16.8a 34.8a 106.3a 16.50 Baythroid 2 EC 0.0313 0.0b 0.3bb 1.8b 1.0b 7.8b 49.5ab 94.50 Baythroid 2 EC 0.0375 0.3ab 0.0b 0.0b 0.0b 1.3b 1.0b 92.50 Baythroid XL 0.0188 0.5ab 0.0b 3.3b 0.5b 13.8b 25.3ab 85.00 Baythroid XL 0.022 0.3ab 0.5b 2.0b 0.0b 2.5b 10.0b 86.50 Warrior 1 EC 0.025 0.3ab 0.0b 0.3b 0.0b 0.0b 1.0b 92.25 Baythroid 2 EC + 0.0313 + 0.0b 0.0b 0.5b 1.0b 2.5b 3.8b 94.25 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0b 0.0b 0.0b 0.0b 0.0b 0.5b 100.00 Warrior 1 EC Stubble 0.03 0.0b 0.0b 0.0b 0.0b 0.0b 3.8b 100.0 Proaxis 0.5 EC 0.015 0.0b 0.0b 0.0b 0.0b 0.3b 6.3b 100.00 Untreated check 1.0a 2.5a 44.3a 15.8a 11.5b 33.3ab *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 22DAT. (Threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 6 Mean number total aphids/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control Imidan 70 WP 1.0 6.0 b 6.0 bc 33.3 b 17.8 bc 25.3 bc 208.8 a 53.25 Imidan 70 WP 1.3 16.8 a 8.8 b 21.3 b 39.0 a 75.5a 172.8 ab -43.75 Baythroid 2 EC 0.0313 2.0 bc 6.5 bc 9.8 b 3.0 cd 21.5 bc 87.7 bcd 81.75 Baythroid 2 EC 0.0375 2.5 bc 2.8 bc 12.8 b 1.0 d 10.3 bc 67.5 bcd 85.00 Baythroid XL 0.0188 2.5bc 3.0 bc 13.8 b 5.0 cd 29.3 b 62.8 cd 81.00 Baythroid XL 0.022 4.5 bc 4.3 bc 9.3 b 1.3 cd 20.0 bc 46.8 d 79.50 Warrior 1 EC 0.025 0.8 c 0.8 c 1.5 b 0.0 d 3.0 c 30.0 d 96.75 Baythroid 2 EC + 0.0313 + 2.0 bc 0.3 c 2.8 b 5.8 cd 10.8 bc 49.0 cd 88.75 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0 c 0.0 c 1.5 b 0.3 d 6.5 bc 61.5 cd 99.48 Warrior 1 EC Stubble 0.03 0.5 c 0.8 c 0.3 b 0.0 d 2.8 c 49.3 cd 97.98 Proaxis 0.5 EC 0.015 1.3 bc 1.0 bc 2.3 b 0.0 d 9.0 bc 39.0 d 95.00 Untreated check 10.0 b 23.3 a 68.8 a 28.3 ab 16.0 bc 152.5 abc *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 22DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Arthropod Management Tests Oxford University Press

EVALUATIONS OF INSECTICIDE PERFORMANCE FOR CONTROL OF ALFALFA WEEVIL LARVAE AND APHIDS, 2005

Mulder, P.G.; Seuhs, S.K.
Arthropod Management Tests , Volume 32 (1) – Jan 1, 2007
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10.1093/amt/32.1.F1
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Abstract

(F1) ALFALFA: Medicago sativa L. “OK 49” EVALUATIONS OF INSECTICIDE PERFORMANCE FOR CONTROL OF ALFALFA WEEVIL LARVAE AND APHIDS, 2005 P.G. Mulder, Jr. Department of Entomology and Plant Pathology Oklahoma State University Stillwater, OK 74078-3033 405-744-5531 FAX 405-744-6039 Email: philmul@okstate.edu S.K. Seuhs Alfalfa Weevil (AW): Hypera postica (Gyllenhal) Pea aphid (PA): Acyrthosiphon pisum (Harris) Blue alfalfa aphid (BAA): Acyrthosiphon kondoi Shinji Cowpea aphid (CA): Aphis craccivora Koch Seven chemical insecticides at varying rates and combinations were evaluated for efficacy in controlling AW larvae and aphids infesting the first crop of a third year stand of “OK 49” alfalfa at the Agronomy Research Station, Stillwater, OK. Pretreatment samples (stubble) revealed very few larvae or aphids; however, samples taken at AW threshold indicated a mean AW population of 73.25 larvae/25stems, while aphid populations remained extremely low (0.25 aphids/stem). The stubble treatment of Warrior was applied on 22 Feb coinciding with timing for annual weed control. Threshold for AW was reached and insecticides were applied on 1 March using a CO pressurized sprayer calibrated to deliver 20 gpa at 19 psi through seven, flat fan nozzles when traveling at 3 mph. Treatments were arranged in a RCB design using plots 3.9 × 9.1 m in size, replicated 4 times. Sampling was conducted 3 and 7 DAT (stubble) and continued 3,7,14, 22, 28 and 35 DAT from the first threshold application, by pulling 25 stems per plot and placing them in standard Berlese funnels to extract insects for counting. Dry matter yields were estimated for first harvest on 3 May by removing forage from a 1 × 5 m area in each plot using a flail-type harvester. Subsamples were dried for determination of moisture content and yields were calculated on a dry weight/acre basis. Weather conditions for the first three days after threshold treatment decreased activity of insects, with no rainfall and a mean daily high temperature of 51.9° F. During the remainder of the trial, through 3 May, a total of 1.09 inches of rainfall occurred and the mean daily high temperature was 52.2 F. The population density of AW was above the economic threshold at the time of treatment and rose to 209.3 larvae/25 stems at 14 DAT in the untreated alfalfa. Samples taken 3 and 7 d after the stubble treatment revealed significant control of AW and aphids even before thresholds were reached in untreated alfalfa (Table 1). These plots were only sprayed during the stubble timing. During the first week after threshold treatment, all insecticides decreased AW larval densities below levels recovered in untreated alfalfa (Table 2). Average percent control for AW was calculated from infestations recovered 3 to 35 DAT. Throughout the test period; most insecticides significantly reduced AW populations below levels recovered in untreated alfalfa. Three DAT, specific insecticides began to perform better than others and this performance remained consistent throughout the trial. Average percent control of AW larvae from 3 DAT to 35 DAT ranged from a low of 10.83 % for Imidan 70 WP (1.0 lb. A.I./acre) to a high of 93.5 % for Warrior 1 EC (stubble - 0.03lb. A.I./acre) (Table 2). In addition, Imidan at the higher rate (1.3 lb. AI/acre) only provided 31.33 % control of AW larvae, while all other formulations provided 70 % control or better (Table 2). From 3DAT to 22DAT, average percent control of all aphids sampled ranged from a low of - 43.75% with Imidan 70WP (1.3 lb.AI/Acre) to a high of + 99.48% with Warrior 1 EC (0.03 lb./AI/acre) (Tables 3-6). Throughout the trial period, the two Warrior treatments and Proaxis provided the greatest and most consistent levels of aphid control. In contrast, alfalfa treated with Imidan often experienced aphid populations in excess of untreated plants. Yield of alfalfa at first harvest ranged from 5563.52 lb./acre in alfalfa treated with Warrior 1 EC (0.03 lb. AI/acre - stubble) to 2706.70 lb./acre in the untreated alfalfa. All treatments yielded significantly greater than the untreated alfalfa with the exception of Imidan 70WP (1.0 lb. AI/acre). The higher rate of Imidan 70WP also performed poorly and yielded significantly less than alfalfa treated with the other insecticides. Table 1 Mean no insects/25 stems (Stubble) AW larvae PA** BAA** CPA** Total aphids Treatment/ Rate/ formulation lbs ai/A 3DAT* 7DAT* 3DAT* 7DAT* 3DAT* 7 DAT* 3DAT* 7DAT* 3DAT* 7DAT* Warrior 1 EC Stubble 0.03 37.5a 33.0a 0.0a 0.0a 0.3a 0.3a 0.3a 0.0a 0.5a 0.5a Untreated check 90.2b 123.0b 4.3b 2.8b 7.5b 5.0a 1.5a 1.5a 13.3b 10.5b * Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). ** PA = Pea Aphid. BAA = Blue Alfalfa Aphid. SAA = Spotted Alfalfa Aphid. CPA = Cow Pea Aphid. DAT = Days after treatment. Stubble sample date was 7 days prior to threshold treatment (2-22-05). Table 2 Mean no. AW larvae/25 stems Treatment/ Rate/ Average** Yield* formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control lbs/A Imidan 70 WP 1.0 129.8ab 141.0a 151.8b 180.0a 169.0a 165.5a 10.83 3082.85bc Imidan 70 WP 1.3 140.8a 95.7b 107.8c 119.3b 134.8b 120.3b 31.33 3338.32b Baythroid 2 EC 0.0313 77.0cd 63.3c 46.3de 28.0c 33.8c 25.3c 73.83 5299.25a Baythroid 2 EC 0.0375 80.5c 74.0bcd 48.3de 30.3c 27.5c 25.8c 72.67 5130.29a Baythroid XL 0.0188 79.5cd 48.3ce 59.3de 23.8c 25.8c 18.8c 75.83 5210.10a Baythroid XL 0.022 73.5cd 64.3c 55.5de 22.5c 28.8c 34.5c 73.33 5305.92a Warrior 1 EC 0.025 67.8cd 58.3c 52.5de 22.3c 20.3c 16.5c 77.33 5216.52a Baythroid 2 EC + 0.0313 + 53.0cd 45.8de 35.8ef 31.8c 17.8c 19.8c 80.33 5341.10a Lorsban 4E 0.25 Warrior 1 EC 0.03 66.5cd 58.3c 42.5de 9.8c 4.8c 16.0c 83.50 5538.34a Warrior 1 EC 0.03 31.5d 27.3e 14.3 f 11.0c 4.3c 8.5c 93.50 5563.52a Stubble Proaxis 0.5 EC 0.015 88.5bc 77.7bc 61.0d 25.8c 23.3c 24.0c 71.33 5330.10a Untreated check 163.0a 166.3a 209.3a 183.5a 167.8a 169.5a 2706.70c *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 35DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 3 Mean no. PA/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control Imidan 70 WP 1.0 2.0b 5.5b 17.0a 7.3ab 13.8ab 90.0a -2.75 Imidan 70 WP 1.3 7.8a 5.5b 4.8c 13.3a 23.5a 41.3bc -78.25 Baythroid 2 EC 0.0313 0.5b 3.3bc 6.3abc 1.0bc 10.0ab 21.8c 76.00 Baythroid 2 EC 0.0375 0.3b 2.0bc 9.5abc 0.8c 5.5b 43.8c 75.75 Baythroid XL 0.0188 0.3b 2.5bc 8.0abc 6.0bc 9.5b 24.8c 61.50 Baythroid XL 0.022 1.5b 3.0bc 5.8bc 1.0bc 9.8b 27.3c 67.50 Warrior 1 EC 0.025 0.0b 0.8c 1.3c 0.0c 1.0b 21.0c 96.50 Baythroid 2 EC + 0.0313 + 0.5b 0.0c 1.8c 2.8bc 3.3b 35.8c 84.25 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0b 0.0c 1.3c 0.0c 4.0b 45.3bc 98.00 Warrior 1 EC 0.03 0.0b 0.8c 0.0c 0.0c 1.0b 33.8c 98.50 Stubble Proaxis 0.5 EC 0.015 0.3 b 0.8 c 1.5c 0.0c 3.0b 22.3c 93.50 Untreated check 2.8 b 12.5 a 15.8ab 8.3a 3.0b 77.3ab * Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). ** Average % control calculated from 3DAT to 22DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 4 Mean no. BAA/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control 70 WP 1.0 3.8bc 0.5b 13.8a 3.3ab 8.3ab 50.5a -.75 Imidan 70 WP 1.3 8.5a 25.0a 5.0bc 7.8a 17.3a 23.0abc -145.25 Baythroid 2 EC 0.0313 1.5c 2.0b 1.8bc 1.0b 3.8b 10.3bc 77.00 Baythroid 2 EC 0.0375 2.0bc 0.8b 3.3bc 0.3b 3.5b 24.0abc 78.00 Baythroid XL 0.0188 0.8c 0.5b 2.5bc 0.8b 6.0ab 12.0bc 83.50 Baythroid XL 0.022 2.8bc 0.8b 1.5bc 0.3b 7.3ab 8.8bc 79.75 Warrior 1 EC 0.025 0.5c 0.0b 0.0c 0.0b 2.0b 8.0c 98.00 Baythroid 2 EC + 0.0313 + 1.5c 0.3b 0.5bc 2.0b 5.0b 8.3c 79.50 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0c 0.0b 0.3bc 0.3b 2.5b 15.8bc 97.50 Warrior 1 EC 0.03 0.8c 0.0b 0.3bc 0.0b 1.8b 11.8bc 96.00 Stubble Proaxis 0.5 EC 0.015 1.0c 0.3b 0.8bc 0.0b 5.8ab 16.0bc 92.50 Untreated check 6.0ab 8.3ab 8.8ab 4.3a 3.8b 40.5ab *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 22DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 5 Mean no. CA/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control Imidan 70 WP 1.0 0.3ab 0.3b 2.3b 9.0ab 3.3b 67.0ab 74.00 Imidan 70 WP 1.3 0.5ab 1.3ab 11.5b 16.8a 34.8a 106.3a 16.50 Baythroid 2 EC 0.0313 0.0b 0.3bb 1.8b 1.0b 7.8b 49.5ab 94.50 Baythroid 2 EC 0.0375 0.3ab 0.0b 0.0b 0.0b 1.3b 1.0b 92.50 Baythroid XL 0.0188 0.5ab 0.0b 3.3b 0.5b 13.8b 25.3ab 85.00 Baythroid XL 0.022 0.3ab 0.5b 2.0b 0.0b 2.5b 10.0b 86.50 Warrior 1 EC 0.025 0.3ab 0.0b 0.3b 0.0b 0.0b 1.0b 92.25 Baythroid 2 EC + 0.0313 + 0.0b 0.0b 0.5b 1.0b 2.5b 3.8b 94.25 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0b 0.0b 0.0b 0.0b 0.0b 0.5b 100.00 Warrior 1 EC Stubble 0.03 0.0b 0.0b 0.0b 0.0b 0.0b 3.8b 100.0 Proaxis 0.5 EC 0.015 0.0b 0.0b 0.0b 0.0b 0.3b 6.3b 100.00 Untreated check 1.0a 2.5a 44.3a 15.8a 11.5b 33.3ab *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 22DAT. (Threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05). Table 6 Mean number total aphids/25 stems Treatment/ Rate/ Average** formulation lbs ai/A 3DAT* 7DAT* 14DAT* 22DAT* 28DAT* 35 DAT* % control Imidan 70 WP 1.0 6.0 b 6.0 bc 33.3 b 17.8 bc 25.3 bc 208.8 a 53.25 Imidan 70 WP 1.3 16.8 a 8.8 b 21.3 b 39.0 a 75.5a 172.8 ab -43.75 Baythroid 2 EC 0.0313 2.0 bc 6.5 bc 9.8 b 3.0 cd 21.5 bc 87.7 bcd 81.75 Baythroid 2 EC 0.0375 2.5 bc 2.8 bc 12.8 b 1.0 d 10.3 bc 67.5 bcd 85.00 Baythroid XL 0.0188 2.5bc 3.0 bc 13.8 b 5.0 cd 29.3 b 62.8 cd 81.00 Baythroid XL 0.022 4.5 bc 4.3 bc 9.3 b 1.3 cd 20.0 bc 46.8 d 79.50 Warrior 1 EC 0.025 0.8 c 0.8 c 1.5 b 0.0 d 3.0 c 30.0 d 96.75 Baythroid 2 EC + 0.0313 + 2.0 bc 0.3 c 2.8 b 5.8 cd 10.8 bc 49.0 cd 88.75 Lorsban 4E 0.25 Warrior 1 EC 0.03 0.0 c 0.0 c 1.5 b 0.3 d 6.5 bc 61.5 cd 99.48 Warrior 1 EC Stubble 0.03 0.5 c 0.8 c 0.3 b 0.0 d 2.8 c 49.3 cd 97.98 Proaxis 0.5 EC 0.015 1.3 bc 1.0 bc 2.3 b 0.0 d 9.0 bc 39.0 d 95.00 Untreated check 10.0 b 23.3 a 68.8 a 28.3 ab 16.0 bc 152.5 abc *Means within columns, followed by the same letter are not significantly different (ANOVA LSD; P = 0.05). **Average % control calculated from 3DAT to 22DAT. (threshold). DAT = Days after treatment. First sample date was 3 days after threshold treatment (3-01-05). Pre-treatment sampled (3-01-05).

Journal

Arthropod Management Tests – Oxford University Press

Published: Jan 1, 2007

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